1. Field of the Invention
The present invention relates to an anti-leakage device for a manual air pump with a pressure gauge.
2. Description of the Related Art
FIG. 1 of the drawings illustrates a conventional manual air pump with a pressure gauge. The manual air pump includes a pressure gauge seat 95 with a passage 96 defined therein. Defined above the passage 96 is a receptacle 97 for securely engaging with an engaging tube 99 of a pressure gauge 98. Glue is applied to fill a clearance existing between the engaging tube 99 and the receptacle 97 to prevent leakage. A screw 100 with a hexagonal socket (not shown) is provided to enclose an open end (not labeled) of the passage 96, and glue is also applied to seal a clearance between the screw and the open end of the passage 96. Nevertheless, application of the glue is difficult to control and requires a skilled worker. Insufficient glue results in leakage, yet over-application of the glue results in a waste in material and causes an aesthetically unpleasing appearance.
It is an object of the present invention to provide an anti-leakage device for a manual air pump with a pressure gauge to allow easy, direct assembly and provide reliable leakage-proof effect.
In accordance with one aspect of the invention, a manual air pump comprises:
a cylinder defining a chamber therein;
a piston rod including a handle mounted to a first end thereof and a piston mounted to a second end thereof, the piston being slidably received in the chamber of the cylinder;
an adaptor including a first end and a second end that is communicated with the first end, the first end of the adaptor being communicated with the chamber of the cylinder;
a pressure gauge including a tubular plug formed thereon, the second end of the adaptor being mounted around the tubular plug such that air in the chamber of the cylinder is flowable to the pressure gauge via the second end of the adaptor; and
a hose including a first end for inflation and a second end for sealingly receiving the tubular plug of the pressure gauge such that air in the chamber of the cylinder is flowable to the first end of the hose for inflation.
The cylinder includes a lower end to which a base is securely mounted. The cylinder further includes an upper end with an outer threading. An end cap is mounted to the upper end of the cylinder for preventing disengagement of the piston. The end cap has an inner threading for engaging with the outer threading of the cylinder, the end cap including a longitudinal hole through which the piston rod extends.
The cylinder includes a transverse slot defined in a lower end thereof. A connector includes a first end mounted in the transverse slot and communicated with the chamber of the cylinder. The connector further includes a second end that communicates the first end of the connector with the first end of the adaptor. In an embodiment of the invention, the second end of the connector and the first end of the adaptor are communicated with each other by a conduit and an elbow.
In a preferred embodiment of the invention, the cylinder includes a transverse slot defined in a lower end thereof. An L-shape connector includes a horizontal section mounted in the transverse slot and communicated with the chamber of the cylinder. The connector further includes a vertical section that is located outside the cylinder and communicates with the horizontal section. The vertical section provides intercommunication between the first end of the connector and the first end of the adaptor. The horizontal section of the connector includes at least one O-ring mounted therearound to provide a sealing effect between the horizontal section of the connector and the cylinder.
The tubular plug includes a first end that is adjacent to the pressure gauge and a second end that is distal to the pressure guage. The first end of the tubular plug includes at least one O-ring mounted therearound to provide a sealing effect between the tubular plug and the second end of the adaptor. The second end of the tubular plug is preferably conic.
A pressure gauge seat is securely attached to the cylinder for receiving the pressure gauge. The pressure gauge seat comprises a through-hole through which the tubular plug extends.
In accordance with a second aspect of the invention, a manual air pump comprises:
a cylinder defining a chamber therein;
a piston rod including a handle mounted to a first end thereof and a piston mounted to a second end thereof, the piston being slidably received in the chamber of the cylinder;
an adaptor including a horizontal section and a vertical section that is communicated with the horizontal section, the horizontal section of the adaptor being communicated with the chamber of the cylinder, the vertical section including a first end and a second end;
a pressure gauge including a tubular plug on an end thereof, the vertical section of the adaptor being mounted around the tubular plug such that air in the chamber of the cylinder is flowable to the pressure gauge, the tubular plug including an outer threading and a conic end;
a hose including a first end for inflation and a second end mounted around the conic end of the tubular plug of the pressure gauge such that air in the chamber of the cylinder is flowable to the first end of the hose for inflation; and
a hollow attaching member including an inner threading for engaging with the outer threading of the tubular plug, the hollow attaching member including a conic section for preventing leakage between the conic end of the tubular plug and the second end of the hose.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.